Question

How does the heat produced in a wire or a conductor depend upon the:

1. current passing through the conductor?
2. resistance of the conductor?

Answer 1

1. Joule's law of heating states that when a current 'I ‘ passes through a conductor of resistance ’R' for time 't' then the heat developed in the conductor is equal to the product of the square of the current, the resistance, and time.
2. Mathematically, $H=I^{2}Rt$. Where, $H=Heatproduced,I=Current,R=Resis\tan ceofwire,andt=Time$.
3. (i) The amount of heat produced in the wire is proportional to the square of the amount of current that is flowing through the wire when the resistance of the wire and the time of a current flow is constant.
   $H\propto I^2(whenR,tarecons\tan t)$
4. (ii) The amount of heat produced is proportional to the resistance of the wire when the current in the circuit and the time of a current flow is constant. $H\propto R(whenI,tarecons\tan t)$